Audiovox SIRIUS FM Switching Module (SATSWB) (SATSWB) Converts built-in, wireless FM modulation into a hardwired FM modulation for the best sound possible Eliminates signal wash from strong broadcast FM stations Designed to work with the Audiovox Sirius tuner and the XM Satellite tuner Measures 2-1/2" x 1" x 2-1/2"